I am trying to help an adoptee determine his birth parents based on DNA matches at different sites. I became involved because he is a 1st-3rd cousin DNA match to many people in my extensive family tree. To help sort through the data, I would like to create a family tree diagram (online or on paper) that only includes people whose DNA has been tested, or their common ancestors. I am willing to mark which people I wish to include in the tree. Is there software that will help me create such a tree, ideally using my gedcom file?
Most FT software allows the export of some or all of the people from a Gedcom file. If your software allows this then select the people for export into a new DNA gedcom. Then open a new project in your FT software using that DNA gedcom as the source data.
If your software does not allow that partial export then have a look at some of the other FT programmes. Family Historian, which I use, has this facility. There may be some online Gedcom editors that allow this too.