SAP UI5 – Table Row shift / Expand

Adding width to sub table worked for me.

Luckily, I still have that code with me. This is something I wrote.

		onRowShiftAction: function (oEvent) {
			var oSource = oEvent.getSource(),
			oRow = oSource.getParent().getParent(),
			oTable = this.getView().byId("idTable"),
			aItems = oTable.getItems(),
			index = 0,
			that = this;
//Loop to get the current item index
			for (var i in aItems) {
				if (aItems[i].getBindingContextPath() === oRow.getBindingContextPath()) {
					index = i;
				}
			}
//Check to count child tables created for different rows to generate unique ID
			if (!this.childCount) {
				this.childCount = 1;
			} else {
				this.childCount++;
			}

			if (oSource.getSrc() === "sap-icon://navigation-right-arrow") {
				oSource.setSrc("sap-icon://navigation-down-arrow");
				var oItemTemplate = new sap.m.ColumnListItem({
					cells: [
						new sap.m.Text({
							text: "{model>Col1}"
						}),
						new sap.m.Text({
							text: "{model>Col2}"
						}),
						new sap.m.Text({
							text: "{model>Col3}"
						})
					]
				});
				// if (!this.oNewTable) {
				var width = window.innerWidth - 100;
				var oNewTable = new sap.m.Table({
					id: "idChildTable" + this.childCount,
					width: window.innerWidth - 100 + "px",
					columns: [
						new sap.m.Column({
							header: new sap.m.Text({
								text: "Col1"
							}),
							width: "4rem"
						}),
						new sap.m.Column({
							minScreenWidth: "Tablet",
							demandPopin: true,
							popinDisplay: sap.m.PopinDisplay.Inline,
							header: new sap.m.Text({
								text: "Col2"
							}),
							width: "6rem"
						}), new sap.m.Column({
							minScreenWidth: "Desktop",
							demandPopin: true,
							popinDisplay: sap.m.PopinDisplay.Inline,
							header: new sap.m.Text({
								text: "Col3"
							}),
							width: "15rem"
						})
					]
				});
				oNewTable.bindItems({
					path: "model>/EntitySet",
					template: oItemTemplate
				});
				oTable.insertItem(new sap.m.ColumnListItem({
					cells: [
						oNewTable
					]
				}), parseInt(index) + 1);
			} else {
				oTable.removeItem(aItems[parseInt(index) + 1]); //On collapse removing table
				oSource.setSrc("sap-icon://navigation-right-arrow");
			}
		}

I hope it will work for you. Worked for me then.