Multijob? Are you talking about:
- Multi-configuration project with multiple Axises
- Regular free-style project with multiple Build steps
In either case, both the free-style and the multi-configuration projects have access to build Parameters through use of environment variables, either $PARAM (Unix) or %PARAM% (Windows) where "PARAM" is the name of your parameter.
Re-reading your question makes me think you are talking about a job triggering Downstream jobs. In that case, you would need to use Parameterized Trigger Plugin to trigger your downstream jobs. Then, under "Add Parameters" dropdown select "Current build parameters" to pass the same parameters from one job to another. Once again, you reference them as you would any other parameter through an environment variable.