Filter on appended table

I have 2 tables (table 1 and 2), and I have appended one to another to get table 3.

The problem is there is a slicer from table 1 that affects a card from table 3, and that is what I want to avoid. It filters the rows of table 1 on table 3 and the card works on the rows of table 2 (that are in table 3).

But It gets weirder (more complicated).

I need to use the slicer to filter the values on the rows of table 2.

This is the measure that I need to make work:

regs = CALCULATE(COUNTROWS('table3');FILTER('table3';'table3'[column_from_table2] = SELECTEDVALUE([column_from_table1])))

Hope You can help me.

Thank You very much!!