You can use a combination of field-level security and a required data step to create an approval step for a stage. This is commonly called stage-gating.
If a data step is marked as required, and the field that is used by the step has field-level security enabled, then users who do not have a field security profile that grants them write permissions to the field cannot complete the step and they cannot continue to the next stage.
For example, you might have a field named Budget that is enabled for field security with the field security profile set so that only one group of managers can enter a value for the Budget field. This field security is applied to the data step in the business process flow. Therefore, a manager must enter a budget value before any user can continue to the next stage of the process.
You must always ensure that all users have a field security profile that grants read privilege to the secured field. If...