I have a menu item 'Level 1' in my site that is "K2 » Categories", single category selected is a parent category(eg 1st level), and the sub-categories switch is enabled. This parent category has two sub-categories (2nd level), and sub-category has a further sub-category each (3rd level). The items are categorised in the 2nd and 3rd levels.

I also have two hidden menu item (Level2-A and Level2-B) "K2 » Categories" for each of the two 2nd level categories that is as explained above, and where the 2nd level is selected and the sub-categories switch is enabled.

I also have a hidden menu item 'Level 3' that is also "K2 » Categories" but with multiple categories selected, specifically the two 3rd level sub-categories as explained above.

When the 'Level 1' menu item is loaded in the browser, all the items expected are shown, however the items that are in the 3rd level sub-categories have URLS showing the alias of the 'Level 3' menu item, whilst the other items have URLS that include the alias of the 'Level 2' menu item.

I would like all the items from Level 3 to have the Level 2 menu item association when loaded from this Level 1 menu item - is that possible ?

Try setting the Level 3 menu as a child of the Level 2 menu.

This gives me :

domain.com / {level 2 menu alias } / {level 3 menu alias} / itemid-alias

Whilst I would prefer to have :

domain.com / {level 2 menu alias } / itemid-alias

... possible ?

Is there a link to your site available?