Add multiple git commands to one line for use in terminal alias

Define as:

push-branch() {
    git push origin "$(git rev-parse --abbrev-ref HEAD)"
}

Use as:

$ push-branch

Note that aliases cannot have spaces in them. You need a function for that. You can replace your current gps alias with a function that takes arguments:

gps() {
    case "$1" in)
    cb) push-branch;;
    *) # whatever your current gps does ;;
    esac
}

You don't need an alias definition at all, which could be solved by a simple function call.

git-push-origin() {
    git push origin "$(git rev-parse --abbrev-ref HEAD)"
}

and just call the function git-push-origin from the command line. Also you could add the function definition to .bashrc to load them at startup.

git has it's own alias system, so you could do

git config --global alias.pushCurrent '!exec git push origin $(git rev-parse --abbrev-ref HEAD)'

which adds the git command

git pushCurrent

but just git push should push the head of the current branch to origin, so you probably have some special case to justify the extra alias, and you can tweak this to fit your needs

You can use substitution $() to use the output of one command as an argument for another command.

git push origin "$(git rev-parse --abbrev-ref HEAD)"

Spaces in aliases or function names are not possible, but even if they were allowed, I don't think you would want to use them, because you had to escape the space in order to call them ("gps cb" or gps\ cb).

If you already have defined your own gps script and want it to behave differently depending on the first argument, you have to use an if or case statement to check the first argument.