There are three ways to join two straps together if really necessary. The first way is to pass one strap through the eye of the second strap, doubling the first strap up to give a total length of 1.5 straps. The second way is to pass each strap through the eye of the other to give a combined length of 2 straps. If you do join two snatch straps by this method, but do nothing else, it will be almost impossible to separate them after use as they will have tightened up and become locked together. As in the second method, a rolled-up magazine can be inserted at the tight spot to ease separation after use.
Snatch straps are a wonderful invention.
The most extreme examples are used to recover bogged army tanks, mind you those straps are thicker than your leg.