hi guys, on the photo that i have just uploaded is my artist impression of tire tread but i'm having trouble making pocket using the sketch on the photo cause of the middle part on each side of the sketch. What can I do to get the same result?

You may leave some incomplete or overlap sketch

So, better you can make small part of that sketch to Pockets
Then try Patten options ( because I can see there 4 times of similar sketch so I recommend this way)
It will be simplified

two suggestions:

1. Since the tread is symmetrical; make the right half and then mirror to get the left.

2. Looks like all the grooves are the same thickness, so simplify the sketch by only drawing the centerlines, then use the Thick option in the Pocket. (similar to Pad image below)