Magura slaves have M8 and M6 fittings ( olive and barb )
One slave has M8 / M6 ( for the main line and crossover ) the other has M6/M6 ( for the crossover and bleed screw ).
You have two choices:
1.
Cut the main line at the required place, and splice the part running to the lever into the top of the splitter, and the remaining bit going to the slave 1 into one of the other part of the splitter. Then, remove the crossover from slave 1, and replace with a bleed bolt.
The other slave needs the crossover cutting down so there is only one barb remaining, one end stays in the M6/M6 slave 2 and the other goes to the hose splitter.
2. Cut the crooss over in half and pres each end into the bottom of the splitter connections. Now cut the main line shorter and press into the top tee connection. The m8/M6 slave will have to be replaced with an M6/M6 slave so each slave has one bleed bolt, and one barbed connection screwed into it.
Either way will work, its just a case of if you have a spare slave that's M6/M6 or not.