For those familiar with TOC thinking, bottlenecks or constraints are a good thing. To those not familiar that comes as a surprise.
A business bottleneck makes improvements easy to manage. If your bottleneck is an internal one, and you know what it is, then your improvement will come from maximising its use and increasing its capacity. That means making sure it does no unnecessary activities, especially re-work. The capacity of the business to increase is limited only by how well you use that bottleneck. Your role as manager of that bottleneck is clear.
What about if you aren't the manager of the bottleneck? What is your role?
Well if you are a "near bottleneck" it's to make sure that you don't take over that role. Process improvements, careful managing of your resources is the watchword, and if bottleneck improvements are likely to put you in the pinch point, shout loudly.
If your area is far removed from the bottleneck, then your role is different. First don't take on work that has to go through the bottleneck that is over their capacity (learn to say "No", even if you can handle the task), then make sure that the quality of your inputs to the bottleneck area are of the highest order. Lastly but not least, what can you do to relieve the bottleneck of work, or better support them to increase their limit?
So whichever role you are in, you have a clear focus to improve the business.