While there isn’t a merge security roles task/operation in CRM, there is a way to combine/add the feature permissions from different security roles into one security role. This is detailed in Step 8 of the Assign feature permissions to a system role section of the Security Guide. It is important to note that the merge operation only affects feature permissions. Tasks, code tables, batches, or any other type of permission will need to be added to the security role manually.
Note: If there are any discrepancies between existing feature permissions and those brought in from the XML file, the settings in the XML file will overwrite the existing settings. For example, if an existing setting grants rights to a feature and the XML file denies rights, the feature will be denied after merging.
To combine feature permissions from multiple roles into one, follow the steps below.
1) Go to the security role whose features are being exported > Features tab > Export to XML (see first screenshot below). 2) Go to the security role to which you want to add the feature permissions > Features tab > Assign feature permissions > Merge from XML file (see second screenshot) > Select the feature permission XML file(s) that were exported.