When you push, you always push the current state of a branch, not individual commits. If you only want to add a certain commit to another branch, cherry-pick is an option: Check out the branch that you want to "add" the commit to, and use git cherry-pick <commit-sha>
or the respective gk feature (right clickt commit -> Cherrypick commit). When you push, the remote branch will be updated and will contain a commit containing the cherry-picked changes.
But why would you only want to use a single commit of a feature? Are you sure you do not want to merge the whole feature branch? Further information about your workflow and branching model would help here.
I suggest you read some beginners literature on how git works. You can find links in the git tag info, like the git pro book