If you're a heavy Streak user, you may have several pipelines that you work with and several other pipelines that your team has shared with you. The left-hand sidebar in Gmail can quickly become crowded and it can be hard to find the pipelines you need to access on a daily basis.

You can hide pipelines that you need to access less frequently by opening up Gmail and clicking on the 3-dot menu next to the pipeline name:

Your hidden pipelines are still accessible under the "Hidden pipelines" label which can be expanded:

To unhide a previously hidden pipeline, select the 3-dot icon on the hidden pipeline and click "Unhide Pipeline":