Thank you Lionel. It works Great with the Tag Field.
I have just some points to clear :
1- the rendering of the Tag Field in front displays IDs of tags and not the label, is there is an API to use to display labels of tags (i can do it with PHP in an override, but an API will be great)
2- the Seblod contents don't seems to be accessible in the list of contents for a Tag (only Joomla Articles are shown for a clicked tag in Frontend). When i click on a Tag in a Joomla Article, the list of results don't display Seblod contents. Is it normal ? How can i add Seblod contents in the list of result for a tag ?
Thanks in advance for any help ;)