You can join the transaction table twice with customer table, first to retrieve sender id and second to retrieve receiver id.
Once you've both ids, you can use ifnull formulae to add a condition to filter in/out the relevant customers
I think you can duplicate customer data, and rename them to Sender and Receiver, and then join them with Transaction.
When edit join condition, use "Edit join Calculation" to edit join condition
number = if [Type] = 1 then [Sender1] end
number = if [Type (receiver)] = 2 then [Receiver1] end
I attached a workbook to show it. Please have a check.
filtering.twbx 6.5 KB