When we use group names longer than 63 characters. As we know, the metadata.name field of any component is limited to 63 characters.

https://backstage.io/docs/features/software-catalog/descriptor-format/#name-required

 There's an example in this section of the documentation on how to change validation rules for metadata fields: https://backstage.io/docs/features/software-catalog/extending-the-model/#changing-the-validation-rules-for-the-entity-envelope-or-metadata-fields

but the to implement this we need to make this changes in the code, so i am opening a feature request for this.