Merge two ranges into one

[nilsr]

Hi!
Im about to make a list that is a summery of two ranges. My two formulas will create ranges that may vary in rows but be the same amount of columns (3). What Im looking for is a way to have a joined formula including both ranges, and when the first is finished, the next one extend the list.
My first formula is complicated but is basically an extended =(A1:C10) (Both 1 and 10 will differ)
My second is a filter formula =FILTER(F1:H20;D1:D20), creating a range with three columns and the same amount of row as values in D1:D20.
Id like to think that a solution like =(A1:C10)(FILTER(F1:H20;D1:D20) would make a list with the outcomes of the two formulas, but it doesn't. Is there a way to merge these two lists using one formulas within one cell?

Thank you very much in advance!

Best wishes.

Nils

[Limor_OP]

Fast answers need clear examples. Post a small Excel sheet (not a picture) showing realistic & representative sample data WITHOUT confidential information (10-20 rows, not thousands...) and some manually calculated results. Just before posting, scroll down to GO ADVANCED, click, and then scroll down to MANAGE ATTACHMENTS and click again. Now follow the instructions at the top of that screen.

[nilsr]

Hi Belinda,
Now I've updated the post with a document. Thank you very much in advance!
Best,
Nils