1. Create a discovery rule in version 2.2. Create all kinds of types and fill all kinds of fields, just to be sure.
2. Import into 5.0
Result:

Invalid tag "/zabbix_export/hosts/host(1)/discovery_rules/discovery_rule(1)/filter/conditions/condition(1)": the tag "formulaid" is missing.

Issue was found during ZBX-19815 and needs to be looked at. Possible that one of the previous converters is not adding the field during conversion.