Hi Hoang,
Thank you for your interest in Syncfusion products.
If your intention is to create your own layout, then you can achieve this by creating a custom version of the Layout Manager class.You can use the custom Syncfusion.Windows.Forms.Diagram.Layout Manager implementation with your diagram to provide the required node positioning logic for the diagram objects. We have samples that is featured with this application.Kindly, refer the following samples,
1.OrgLayout ( Diagram.Windows\Samples\In Depth\OrgLayout )
2.OrgChart (Diagram.Windows\Samples\Layout Managers\OrgChart)
The OrgChartManager class in the samples is an implementer of the Essential Diagram Layout Manager functionality.We follow a very simple layout management algorithm that calculates the sub-employees associated with each employee and allocates space accordingly. More efficient management strategies may be used for better diagram layout.By this way you can control the layout of the nodes on the Diagram.
As with the other issue "group symbols together as one symbol", you can subclass the Symbol class and create as many nodes as you require which as a whole we call as a single "symbol".For your reference I have created a sample implementing this feature,please look into it.
Please let us know if you have any queries.
Regards,
Praveena.
CustomSymbol0.zip