Auto Complete Rule to default the notice period

Summary:

We have a requirement where we need to default Notice period field based on country, grade and time served in organization. Country and Grade parts are available for verifying in same business object(Worker's Assignment). But how do we check time served, seniority date / hire date is to fetched from different business object.

If anyone had similar or related requirement, their help is appreciated.

Content (please ensure you mask any confidential information):

Version (include the version you are using, if applicable):

Code Snippet (add any code snippets that support your topic, if applicable):