Official Bosch Instructions to open filter pump cap.
A common problem with the pump filter on recent Bosch washing machines is if enough or particular object clog it, it can seem impossible to unscrew and clear.
I watched a you tube clip about how to clear it and that seemed doable until I realised there are star headed screws holding the relevant parts together. I’d have to borrow tools to do it that way.
I realised the issue is leverage. I happened to have this piece of jarrah (hardwood) decking scrap which has a cut out for manual scroll sawing. It turns out to be exactly the right tool to give gentle leverage without damaging the plastic screw cap.
Hopefully you can use this image taken on a 1cm grid to create a general template to make one yourself.