Well, the exact solution to your problem will depend on the Talend tool you are using:
In case you are using:
Talend Open Studio: In Talend Open Studio, all you need to do is export the Job as a zip file and then invoke it however you like(by scheduling it or manually from the command line). Just keep in mind, in case your Job is using shared resources then it might lead to concurrency issues as each time the job is executed will require the same resources.
Commercial Product: In this version, you can access the Talend Administration Center using which you can schedule the same job multiple times and that too with different contexts. Also, in the commercial version, a tParallelize component is available as well, which you can execute other Jobs multiple times.
In both the cases, you will have to make sure you are using context variables so that no scope issues occur.