In this scenario, the request form is used as a trigger. Once a purchase requisition is created through the request form, the approval process will start. You will modify the form’s look by using a table view and also provide dropdown menus with pre-populated data to choose from.
Make sure that you are in the Process Overview
Choose the three dots on the form of your trigger
Select Open Editor

You are now in the Forms Editor, where you can design and modify the layout and input fields. On the left side of the canvas, you’ll find various options to choose from, such as text fields, numeric fields, and tables.
Select the three dots on the Description field and choose Delete.

Similarly, delete the following entries as well:
Add a Dropdown field beneath Item Details.
Add the name Select Cost Center and select the Required checkbox on the right.

Choose the Data Source option in the Data to display section, then select the Browse library button.

You will prepopulate the dropdown field through an action, so users can select the options available in the SAP S/4HANA System. While it’s possible to enter values manually, in this instance, we prefer to retrieve existing data from the system for the dropdown selection.
Actions are a concept of how we can easily maintain APIs within SAP Build Process Automation that allow the process to connect and communicate with the other systems, e.g. retrieve and post data from SAP S4/HANA System.
Once in the library, select the action Reads all available cost centers by selecting Add.

Choose Create Destination Variable from the Destination Variable dropdown menu.

Provide the following information to the Destination Variable
Select Create

Select CostCenter from the Destination Variable dropdown menu.
Under Available Data, type CostCenter then select the Cost Center string option.
Select Save

You will now create a table view for the input fields and also pre-populate them using the same action.
Drag and drop a new Table field to the Form. Name it Line Items.

Select the plus icon within the newly created Line Items table, then choose the Dropdown option.
Insert the Name Material and select required.

Navigate to Data Source and choose Browse Library.

Once in the library, select the action Reads all product materials. by selecting Add.

In the Destination Variable dropdown menu, select Create Destination Variable and enter the following details:

Select Create
Select the MaterialCodes option from the Destination Variable dropdown menu.
Under Available Data, type Material then select the Customer Material string option.
Select Save

Select the plus icon, and add another Dropdown input field. Name it Plant, and make it a Required field.
Under Data Source, select from library. Select the Action Reads all Product materials by selecting Add.
Under Destination Variable, select MaterialCodes.
For Available Data, type Plant and select Plant string. Select Save

Create another Line Item by selecting the plus icon next to the Plant input field…
Select Dropdown as the field type. Name it Base Unit, and make it a required field.
Fill in the following values for the Manual option, then select Save.
PC
KG
EA

Add another field into the table by selecting the plus icon next to the Base Unit input field.
Select Text as the field type. Name it Quantity, make it a required field then select Save.

Drag and drop another Dropdown field below the table. Name it Company Code, and make it a required field.
Under Data Source, select from library. Select the Action Reads all available cost centers by selecting Add.
Select the CostCenter option from the Destination Variable dropdown menu.
Under Available Data, type Company and select the Company Code string option.
Select Save

Create a new Text field and call it Purchasing Organization and select the Required checkbox on the right.

Create a new Text field and call it Purchasing Group and select the Required checkbox on the right.

Save your work by selecting the Save button in the top right corner. You are done with the layout and input fields of the approval form.