When you arrive, you need to be in the LEFT lane all the way around the car park, make sure you let the staff members directing traffic see your Blue Badge so they will let you stay in left lane... the disabled parking is right near the park entrance.
The bag search is now outside the access gates, ordinary bag search queues are to right and left, there are two lanes in the middle, left one is bagless entry and right one for disabled and hotel guests skips almost all the queue.
Once through that there are toilets inc disabled, before you pass thru onto bridge and into Dome, which has coffee shop, shop, etc and a disabled toilet on the left side of the exit from Dome into park proper.
The accessibility hub is just below and to front of the Dome - no lift, you need to follow path round, ask a staff member if you aren’t sure which way to go.
We don’t usually make use of that as Martin can’t do any rides any more, except Teacups which never get long queue anyway! Think would be bit of a wait to get the Ride Acess Pass at busy times, but worth it if you are still able to do the rides - staff normally very helpful and friendly in our experience.
If you are looking for some place to make the heatwave bearable, you could do a lot worse - Tidal Wave splash zone you can get wet and cool off without queueing, lots of free water and sun cream available (inc big glasses of soda water with lashings of ice, in the restaurants!) And of course you are never far from a toilet, lol - Dome has Changing Places one.