Is it possible to synchronize a file between projects?

Question

GitLab

Hello. Decided to install and configure GitLab. I talked with a fellow programmer about filling it (gita), and a question arose.
For example, there will be 2 projects, each of which has a certain set of data, and there is also something in common between them, these are the sources for service.exe. A couple of groups of people can edit it according to the realities of one of the projects. Is it possible in GitLab to make it so that, for example, by adding a new piece of code in one project, this will be reflected in another project. Added/removed. Because this service.exe performs the same functions in these two projects. But it is not planned to separate it separately for each project. I hope I was able to formulate the question clearly.
On the client side of TortoiseGIT.

Answer 1

move the shared code to a separate repo. include this repo in your projects as a submodule.
or smoke about subtree.