For a list of all available endpoints, see the Swagger documentation at the API root.
Filters are specified via GET parameters. For instance, to limit the list of positions to only those requiring German, one would access:
/api/v1/position/?languages__language__name=German
You can combine filters. To look for positions that require German with at least a spoken proficiency of 2+, you can use:
/api/v1/position/?languages__language__name=German&languages__spoken_proficiency__at_least=2plus
Note the use of 2plus instead of 2+ - this is because + is a reserved delimiter in URLs.
To search for a position where multiple values are true (via logical AND) combine them into a single parameter. For example, positions that require both French and German:
/api/v1/position/?languages__language__name=German,French
To search where either case is true (via logical OR), use the in lookup:
/api/v1/position/?languages__language__name__in=German,French