MASTER SYNC ON BOSS RC300 ?

[MangoRob]

Hi everyone, im sorta new here, ive done a search but cant find anything that pertains to doing a MASTER SYNC option on the rc300 like i have on my boomerang3,

so basically,
i want to be able to do a simple 1bar rhythm on trck 1
                                       then 4bars on track2
                                       then 8bars tracks on track3
and be able to switch between track 2 & 3 while track 1 keeps playing.
any help would be greatly appreciated.
thanks all