You can only start another NWC component workflow using the call a workflow action.
Your other option would be to have NWC workflow start with a start trigger of SharePoint online item created or item modified.
I use the 'item modified' start a fair bit with combined with using a condition.
Choice or boolean column types in sharepoint work well for this purpose.
For example on your list or library have a column 'Start Workflow 2' as Yes/No
NWC workflow started on item modified where column = 'Start Workflow 2'.
Just be sure in your 'Workflow 2' design to update the list item to set the column 'Start Workflow 2' back to No.
One of the frustrating elements of calling/starting workflows across platforms is the lack of output.
ie NWC WF calls other NWC component WF allows output variables back to the calling WF.
O365 WF calls NWC component WF does not allow output variable back the O365 WF.
Gavin