In the US, I think it would be covered by this: https://www.law.cornell.edu/rules/frcp/rule_24 https://www.law.cornell.edu/rules/frcp/rule_24 So presumably the

In the US, I think it would be covered by this: https://www.law.cornell.edu/rules/frcp/rule_24 https://www.law.cornell.edu/rules/frcp/rule_24 So presumably the analogue to that in Spain.