You can select the option Share updates since then to only share records that have been inserted or updated since the last share, shown in the Last share time field.
This option will also be applied on: Scheduled Bulk Shares, Run another bulk share like this, and Execute now.
Procedure
To share records that have been inserted or updated since the last share, follow these steps:
Navigate to Bulk Share
In ServiceNow's left side navigation window, navigate to Perspectium > DataSync > Bulk Share or simply type and then click on Bulk Share.
Enable the option
Under Filter and Enrichment, check
Then, follow the rest of the steps in Create a ServiceNow bulk share.