2 possibilites :

being able when creating a job to choose a parser for this plugin + also choose a value for one or two or 3 parameters.

The number and name of parameters could be configured in the parser configuration in jenkins configuration.

Then these parameters could be used in the groovy script.

Exemple of use :

parser toto choosen with parameter "severity = error only"

then in the groovy script we could ignore all warning that don't have the severity error.

currently each time a project need a little modification of a parser, I need to create a new parsed that is quite identical to the first one. When a bug is detected I need to correct several parser.

only one parser with configuration is cost and time effective