I downloaded a couple of poses in sims 2 and unpacked them in sims 2 downloads folder and enabled them in game but when i search hobbies>> miscellanos i can't find them
so how do i make them appear and work properly?

They may not be in hobbies -> misc - the best thing would be to ask the creators themselves, assuming your other CC is working. Make sure you installed all the files, too.

Poseboxes are usually in hobbies -> misc, or in General -> misc. A few will show up in hobbies -> creative (JD's boxes).
With the exception of the poseboxes that draw poses from ingame, there will usually be two files, one that has the posebox itself, and one with the poses.

To use them, you place the posebox on the lot, pick a sim, click on the box, and choose a pose. The sim will usually start the pose immediately.

Some boxes have start/stop functions, some have a universal stop button, and some will show a regular action icon that you'll have to click to stop the pose.

To pose two sims close to each other, use OMSPs (the black one in the shiftable set here at MTS is perfect).

If you have AL, I also recommend the Freezer Clock (also found at MTS), which makes it easier to pose two or more sims.

I changed the catalogue sort so they ALL appear in Hobbies>Misc (for $1) AND are available on both home and community lots. It's worth doing because it's very annoying to set up a shot only to find the box you need is NOT THERE.

Even better is to add them all to a collection then hide them from the catalogue, so they don't clutter up your regular gameplay.

I realise I'm going off topic here, but could you explain how to do that?

When I first got Sims 2 back in the day, I went into the collections tab, saw that it was just sorted 'themes' that mostly didn't even fit the category it was in and since then, I lost interests in it and almost forgot it existed. Now, with my neurotic download mania and 10+ GB downloads folder, my catalogue is cluttered with objects I do want to keep for later use, but can't use for anything at the moment. Such as 50 different farm/country-related items, 50 shop-related items and so on and forth. If it's really possible to not only create one's own collections, but also hide said items from the catalogue after doing so, I would be a very happy person.

It helps to link to the content you are asking about. There are also some poses that are not boxes but get added to your sim menu. Hula and more and Toddler poses are two that I have like that.