Hi Me,
Thanks for contacting Syncfusion support.
Currently, we did not have the in-built support for resizing the split bar based on the contents or custom components width in split panel. So, we suggest you to use the paneSize field in properties.
Refer to the following API link:
Please refer to the following sample:
If the above does not meet your requirement, kindly get back to us. we will happy to help you.
Regards,
Selvamani S.