One way to carve out a piece of a family line from a full Family Tree Maker data base file is to create a Decendant Tree (or Ancestor Tree, depending upon what you are trying to isolate) for the INDIVIDUAL that you are going down (or up) from. Then use the "Copy/export individuals in the Decendant (or Ancestor) tree" command which is found in the FILE Menu while the tree is displayed. When you save the copied file, it will contain all the information just for those individuals in the tree you created. You can then create a GEDCOM file from it if that's what you are after. (You can select the Individual from whom you want to create the tree by clicking on him/her in a Custom Report list for the initial data base. Create the Decendant or Ancestor Tree when the Family Page for the individual is displayed)