Hi Ramón,
I have tried with one example.
Let´s assume that we have a job "testtest" inside a first level "job_folder_test" folder and inside a second level "sub_folder_item name" folder. Please, notice that the name of this folder has a space.
I used the following command to delete the jobs 1 and 2.
java -jar ~/.jenkins/jenkins-cli.jar -s
http://localhost:9090 delete-builds 'job_folder_test/sub_folder_item name/testtest' '1-2'
Again notice that i put the folder path within commas so that the space is recognized.
I hope it helps
Best regards,
Jonathan