"to the battery" is also a somewhat nonsensical concept, because there are single conductors within the battery, from the cells to the connectors. So there will be a T- or Y-style split at some point for sure.
The main idea is to make sure that:
1) H-bridge is wired to battery using sufficiently thick wiring all the way
2) digital electronics are not on the "direct path" between the battery and the controller
Easiest is to make a Y split right at the battery connector, with a thinner cable going to digital electronics, and a thicker cable going to H-bridge.
There are other options. For example, you can wire thick cables to the H-bridge, and then use thin cables from H-bridge input to digital electronics. This is slightly less ideal, though.
In any case, you probably want to clean up the microcontroller input with a 10-100 uH inductor and a 100-1000 uF capacitor before the actual entry to the MCU.