How to automate merging process in spreadsheet

i am working in 3 copy of the same spread sheet and i use merge tool come with LibreOffice but i find myself in loop doing the same process all i want is to fill the empty cell in the original sheet from other copy is automatic option for this

Why 3 copies of filling cells when the result would be identical? Or isn’t it? If you just want the same input in always the same cells (or similar range of cells) then you can use external references to one source document in two other documents. Like


or use the point and click method described in To Reference a Cell in Another Document.

You can pull right and down or copy&paste such a formula like any other formula to fill a range, respecting the relative/absolute addressing parts in column and row.

did you use compare or merge document tool in LibreOffice before