Customer was able to limit the nested repository path with "oc adm catalog mirror" by using the argument "--max-components" but there is no alternate solution along with "oc-mirror" binary while we are suggesting to use "oc-mirror" binary for mirroring.for example:
Mirroring will work if we mirror like below
oc mirror --config=./imageset-config.yaml docker://registry.gitlab.com/xxx/yyy
Mirroring will fail with 401 unauthorized if we add one more nested path like below
oc mirror --config=./imageset-config.yaml docker://registry.gitlab.com/xxx/yyy/zzz

We can reproduce the issue by using a repository which is not supported deep nested paths

1. Create a imageset to mirror any operator

kind: ImageSetConfiguration
apiVersion: mirror.openshift.io/v1alpha2
storageConfig:
  local:
    path: ./oc-mirror-metadata
mirror:
  operators:
  - catalog: registry.redhat.io/redhat/redhat-operator-index:v4.12
    packages:
    - name: local-storage-operator
      channels:
      - name: stable

2. Do the mirroring to a registry where its not supported deep nested repository path, Here its gitlab and its doesnt not support netsting beyond 3 levels deep.

oc mirror --config=./imageset-config.yaml docker://registry.gitlab.com/xxx/yyy/zzz

this mirroring will fail with 401 unauthorized error
 
3. if  try to mirror the same imageset by removing one path it will work without any issues, like below

oc mirror --config=./imageset-config.yaml docker://registry.gitlab.com/xxx/yyy 

Need a alternative option of "--max-components" to limit the nested path in "oc-mirror"