Sync Filters are created automatically based on certain instances that occur while AutoTrading. The main situations these are created are:
1) If you choose to not enter open positions when setting up AutoTrade, a Sync Filter is created to prevent you from joining the existing positions
2) If you do not have permission for a certain instrument or symbol
3) If you manually adjust or close a trade using the manage positions screen
That being said, although Sync Filters cannot be manually created, they can be managed by you.
AutoTrade -> Control Panel -> Advanced: Sync Manager button
If you do not see the button, this means you do not have any Sync Filters to manage.
Please keep in mind that if you remove a Sync Filter, you cannot re-create it. So pay extra attention to what you are doing before you actually delete a filter. Deleting filters will result in AutoSync taking action. Anything that the filter was "preventing" will no longer be in place and AutoSync will do its magic and get your account in sync with the strategy now that the filter is deleted.
Note: You cannot create a SyncFilter.