ConfigSync supports App filters and Object filters. Below is an example configuration in the fusion-config-sync section of the Helm chart that synchronizes all apps but only specific objects:
pub:
  apps: "*"
  objects: &objects
    # filter tmp file names
    name-filter: ".*_lw_tmp.*"
    # possible modes: all, any
    json-matchers-mode: "any"
    # filter audit properties by json pointer
    prop-filter: >
      /created,
      /modified,
      /createdAt,
      /updatedAt,
      /updates
    solr-configs:
      name-filter: "^(system_|_default).*"
    solr-collections:
      name-filter: "^system_.*"
    apps:
      prop-filter: >
        /properties/previousCollectionId
    configurations:
      name-filter: "^config-sync.+"
    datasources-v2:
      prop-filter: >
        /_id
    blobs:
      name-filter: "^quickstart/.+"
      json-matchers: >
        /contentType=.+
    collections:
      name-filter: "^system_.+"
    spark-jobs:
      # data-migration jobs
      name-filter: "^lw_(import|export)_.+"
    tasks:
      # data-migration tasks
      name-filter: "^lw_export_finalizer_.+"
    index-pipelines:
      prop-filter: >
        /properties/secretSourcePipelineId,
        /stages/secretSourceStageId,
        /stages/licensed
    query-pipelines:
      prop-filter: >
        /properties/secretSourcePipelineId,
        /stages/secretSourceStageId,
        /stages/licensed
    users:
      json-matchers: >
        /username!=admin
    roles:
      json-matchers: >
        /name!=admin
    groups:
      json-matchers-mode: "any"
      json-matchers: >
        /id=_shared,
        /isSystem=false