Hi,
You can follow below steps:
1. Add a form with Class_List as a data source.
2. In that form, unlock changes to Student ID DataCard.
3. After unlocking changes, you will be able to add input fields. Now you can add combobox to this data Card. Set the visible property of Student ID to false.
4. To achieve the functionality there are 2 ways
A. OOB way to Set the items property of combobox to Student_List and then modifying the Fields property that is visible on the right side to have "Double layout". Double layout can display 2 fields (ID and FirstName/LastName from Student_List). To save ID in ClassList, set Update property of DataCard Student ID to ComboBox1.Selected.<StudentIDColumnName>
B. There is another way where you can create a collection on screen visible property:
ClearCollect(comboStudentList, AddColumns(Student_List,"ID+FirstName+LastName", Concatenate(StudentID, " - ", 'First Name', " - ", 'Last Name') ) ). After creating a collection, set items property of combobox to comboStudentList.ID+FirstName+LastName. To save the ID in ClassList, you will have to add below formula on Update property of Combobox added First(Split(ComboBox1.Selected.'ID+FirstName+LastName',"-")).Result
