How to get OData Context from parent Context in UI5

I'm using the OData V4 model in UI5. I've created a binding with some expands in it and now I try to obtain the context of a child entity.

Here is the code how I bind entities to some element. As a result I get an object with on 'SomeEntity' and an array with 'SomeOtherEntity' as a property.

oPage.bindElement({
    path: /SomeEntity(id),
    parameters: {
        $expand: {
            SomeOtherEntity: {
                $select: ['ID', 'name', 'sequence'],
                $orderby: 'sequence'
            }
        }
    }
});

Now I can get the context of the binding with oPage.getBindingContext() and can execute methods like requestObject, setProperty, create and delete from this object.

What I want is to obtain the context of one of the 'SomeOtherEntity' properties to (for example) delete one of them. I have no idea how to accomplish this. Anybody has an idea?

You can create an own ListBinding to SomeOtherEntity and filter the desired set.

(I'm not quite sure, but it might be necessary to trigger a refresh on the ListBinding to force an initial load)

After the data is loaded (dataReceived-Event), delete all the Contexts. Each Delete returns a Promise and you can proceed with a Promise.all.

var oDataModel = this.getModel();
var aPromises= [];
var oListBinding = oDataModel.bindList("/SomeOtherEntity", undefined, undefined, new Filter("ID", FilterOperator.EQ, sIdToDelete), {
        $$operationMode: OperationMode.Server
    });

oListBinding.attachEventOnce("dataReceived", function (oEvent) {
    var aContexts = oListBinding.getContexts();
    aContexts.forEach(function (oContext) {
        aPromises.push(oContext.delete("$auto"));
    });
    Promise.all(aPromises).then(function () {
        /* Cleanup after Deletion
    });
});