Insert heirarchial chart in writer document
Please, edit your question to elaborate a bit more. How do you design your hierarchical chart? Which which tool? Draw (best choice IMHO)? How does it relate to your document content?
Note that there is no tool in LibreOffice to assist in the specific task of building a hierarchical concept map, like you can find in other software suites. As @ajlittoz says, Draw is the tool of choice within the LO suite.
Draw is a general purpose vector drawing app, and among other things it is also suitable for drawing concept maps. However, Draw has no inherent knowledge of different map types. You will have to add connectors and organize into levels yourself.
If you already have the chart and just need to insert it, there should be an “export” function in the app you used to create the chart. Copy/paste should also work if the app runs on the same computer where you have LO running.
If this doesn’t lead you to any solution, please provide more detail (as already suggested by ajlittoz).