Find match for 2 fields in different table, then recognize in 3rd field

What I would do here is build a formula checkbox field on the tasks table to tell you if that task has been reported (a child record was added)


Assuming your relationship is set up such that 1 task record can have many report records, you can create a summary field that counts the number of child report records have been created.


Then, on the task table, your formula checkbox field formula would be something like: if([# of reports]>0,true,false)


Let me know if that was helpful.