Make the menu dynamic (or re-generate) and just apply new settings by an smart action would do the job i guess.

Tuur

hm, i dont think that works.

why not define both your sidebars and set one of them to visible=false / enabled=false
and the onclick action just switches this, for example

I guess you use some kind of side bar similar to or same as my Side Menu. If you explore this (see online link) you will see there is option to change menu language. What this is doing? It is dynamically changing menu items. Something very similar you have to do for your phases. Don't know how phases are choosen but exploring the code from menu, adapting instead of language to use phase you can achieve that. In case of need I can directly support you as I am dealing with different menus last years (in that case come to me via mail with details on support needs + working project package to work with)