At the beginning of the cycle, all OKRs are aligned. Even though each team works on its own and independently, all OKRs taken together must implement the defined strategy or vision. So you synchronize the OKRs for the different levels and areas in the company that participate and for which you have created OKRs.
This approach is fundamentally different from the cascading approach often found in other companies. Here, milestones of higher levels serve as targets for lower levels in the company. This runs counter to an agile mindset. Cascades are typical of a top-down structure, whereas objectives in OKRs also work bottom-up. Alignment can thus be seen as the opposite of cascading.