You have created a page layout for Leads using "Lead Category" as Instance Type, however when you open the Products facet and try to add a new product, the queries appearing under Products field are showing the Master Layout queries and not the queries for the specific layout you have created.
SAP Cloud for Customer
Reproducing the Issue
1. Log into the system with the affected user.
2. Go to Sales then Leads work center.
3. Open any Lead.
4. Go to Products facet.
5. Click in Add button.
6. Click in Products field OVS.
7. Observe that the queries appearing are the same from the Master Layout and not from your specific layout.
This is the system behavior.
Even you are opening this screen from a Lead document, the screen you are checking belongs to Materials BO and not for Leads BO, so the layout created and assigned to Leads BO under Assign Layouts settings will not be reflected in this screen.
You need to assign the layout you have created to Materials BO under Assign Layout settings in order to have the layout working properly for this Product's screen.
If you go to Materials BO and try to find the "Lead Category" field you are using as instance type in this scenario, the field will not appear there.
As the field does not belong to Materials BO, the field will be only available to Leads BO Instance Type option.
Also, the Instance Type option will bring only the fields of Code List type.
If there is no field to be added on Instance Type for some BO, it means that you do not have any Code List field available for this BO.
Page, Layout, Leads, Products, Materials, Missing, Not, Working, , KBA , AP-RC-UIF-FLX , Page Layout & Key User Configuration , How To