Need help with report

I am trying to create a visual which will essentially tell me when sales orders are invoiced. The data source is a transaction lines table, which contain both the sales orders and invoices so it is simple to create a visual to show the number of sales orders per month and invoices generated per month sperately. However, I am trying to get a position where I can click on a sales order visual, say the sales orders booked for Oct 2021 and I want to see what months the invoices we raised. There is a field in the transaction lines table that gives you a "created from field", which is the document number of the sales order the invoice was generated from, so there is a relationship between both records, I just haven't managed to get the report to work as desired. It has been suggested that maybe a drill through will work, or a meause in the second visual that uses the SELECTEDVALUE() function, but as yet I can get it to work, it would be great if someone can help!