Correct invalid groups_attribute_path option + added details for nested groups (#61202)

* Correct invalid groups_attribute_path option + added details for nested groups

* Update docs/sources/setup-grafana/configure-security/configure-authentication/keycloak/index.md

Co-authored-by: Christopher Moyer <35463610+chri2547@users.noreply.github.com>

* linting

Co-authored-by: Christopher Moyer <35463610+chri2547@users.noreply.github.com>
Co-authored-by: IevaVasiljeva <ieva.vasiljeva@grafana.com>

docs/sources/setup-grafana/configure-security/configure-authentication/keycloak/index.md

@@ -109,7 +109,14 @@ This will add the `groups` claim to the id_token. You can then use the `groups`
 
 ```ini
 [auth.generic_oauth]
-group_attribute_path = groups
+groups_attribute_path = groups
+```
+
+If you use nested groups containing special characters such as quotes or colons, the JMESPath parser can perform a harmless reverse function so Grafana can properly evaluate nested groups. The following example shows a parent group named `Global` with nested group `department` that contains a list of groups:
+
+```ini
+[auth.generic_oauth]
+groups_attribute_path = reverse("Global:department")
 ```
 
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