Filtering a lookup via a multi-select field

Filtering a lookup via a multi-select field

Hi there,

 

I have a filtered lookup called Assets which only shows assets that are added to a development. (Development A has Asset A and B, Development B has Asset A, Asset B and Asset C. When you select Development A you can only see A and B)

 

That works great and is a multi select tool so if you select Development A, you can then select from Assets A-Z as per their record.

 

What I would then like to do is have a subform where you select testing requirements (e.g. Asset G needs Test 1 and Test 2, Asset B needs only Test 4 and Test 5) but I can’t get the subform lookup for the testing requirements to be filtered by the selections made in the Asset lookup.

 

Can you help?