set recordsource of sub form to allow edit of records

[Alib]

I want to be able to update a record.



I have a form with a combobox (cbxTrainee) and a subform. I want the subform to show all the records that belong to the name that is selected in the combobox (cbxTrainee) when I click the button (btnFind).

How do I set the recordsource of the subform to the sql string created when clicking the button.

The subform data also needs to be editable

[orange]

Here's a free youtube video that shows a main form with a combo which controls ( via selection)
the record on the mainform and related records on the subform. Concept is same on 2016.