Normally, once a motion or an amendment is before a committee, the committee can dispose of it only by taking a decision, but there are other things. A committee can agree, if there's consent, to either withdraw the motion or adjourn the debate. Once it's no longer debating that motion, it can move on to other business. Then the business could be taken up by the subcommittee.
It's entirely up to the committee's discretion. The committee could decide to adjourn the debate on this motion and proceed to consider other issues, or the committee could, with unanimous consent, withdraw this motion from it entirely and deal with it in subcommittee. Also, if it adjourns the debate here, it could deal with it in subcommittee as well.
There are some options for the committee if it doesn't want to take a decision on this motion right now.