Custom Permalink for Taxonimie and Custom Post Type

i hope you can help me.
I have an Custom Post Type with an taxonomy and i want to change the permalink of the displayed taxonomy term.

Actually my Urls looks so:
meineseite.de/posttype/ – archive site
meineseite.de/posttype/post/ – single post page
meineseite.de/taxonomy/term – term page of the taxonomy

and i want that the last url in list looks like this:
meineseite.de/posttype/taxonomy/term – term page of the taxonomy

This Setting should be only work for this one custom

I read already something about the rewrite engine and saw some examples, but i don’t get it. Everything i try destroys my website. So i hope that some of you can give me the korrekt answer. Thanks.

SOLUTION
For my case i only had to add this code to my taxonomy:

'rewrite' => array(
            'slug' => 'mypostype-wich-should-be-displayed-before-the-taxonomy', // This controls the base slug that will display before each term
            'with_front' => false // Don't display the category base before 
        )