You can merge all the changes from FeatureB into the FeatureA branch you want (it’s a good idea to mark the merged versions, since subversion will not do this for you - the svnmerge.py tool does this, but I would rather keep the record myself). Then undo / delete the changes you do not want (for example, as you noted in the previous question, are part of the changes).
: ", FeatureA FeatureB trunk, , , , FeatureB". , . , / , FeatureA FeatureB, trunk?
, , , .
FeatureA. , FeatureA .