There's no official way to show something like this, but maybe you can add some kind of visual clue. In the example below I'll use an error bar to try to indicate a point is beyond some limit.
Here's the data. Column C has the Y values, which may exceed the limit in cell D2. Column D has the value in column C, or the cut-off value if column C exceeds it. Cell E2 has the length of an error bar to use in column E if column C exceeds the cutoff.
Formulas (filled down the range):
Cell D4: =MIN(C4,$D$2)
Cell E4: =IF(C4>$D$2,$E$2,NA())
Select B3:B7, then hold Ctrl while selecting D3:D7, so both regions are selected, and insert a chart (I've used a line chart, the top left chart).
Select the plotted series, click the plus icon floating beside the chart, and add error bars (top right chart).
Format the error bars. Under direction, choose Both. Under Error Amount, choose Custom, click Specify Value, and for the Plus error bars select E4:E7, and for the Minus error bars enter 0 (bottom left chart).
Format the error bars. Under End Style, choose No Cap. Click the paint can icon, choose a thicker line width, and choose an appropriate End Arrow Type and Size.