Just remove the filter to see everyone.
;WITH [RoleMembers]([member_principal_id], [role_principal_id])
AS (
SELECT [rm1].[member_principal_id],
[rm1].[role_principal_id]
FROM [msdb].[sys].[database_role_members] [rm1] (NOLOCK)
UNION ALL
SELECT [d].[member_principal_id],
[rm].[role_principal_id]
FROM [msdb].[sys].[database_role_members] [rm] (NOLOCK)
INNER JOIN [RoleMembers] AS [d]
ON [rm].[member_principal_id] = [d].[role_principal_id]
)
SELECT DISTINCT
[rp].[name] AS [database_role],
[mp].[name] AS [database_user],
[mp].[type]
FROM [RoleMembers] [drm]
JOIN [msdb].[sys].[database_principals] [rp]
ON ([drm].[role_principal_id] = [rp].[principal_id])
JOIN [msdb].[sys].[database_principals] [mp]
ON ([drm].[member_principal_id] = [mp].[principal_id])
WHERE [rp].[name] LIKE 'SQLAgent%'
AND [mp].[name] NOT LIKE '##%'
ORDER BY [rp].[name]
This should produce output similar to this:
or
database_role database_user type SQLAgentOperatorRole PolicyAdministratorRole R SQLAgentReaderRole PolicyAdministratorRole R SQLAgentReaderRole SQLAgentOperatorRole R SQLAgentUserRole dc_admin R SQLAgentUserRole dc_operator R SQLAgentUserRole MS_DataCollectorInternalUser S SQLAgentUserRole PolicyAdministratorRole R SQLAgentUserRole SQLAgentOperatorRole R SQLAgentUserRole SQLAgentReaderRole R