Although you don't say so, the suggestion that you need to "see the big picture" might indicate that you are a great tactician. More and more organizations are flatter and leaner these days. This means good, competent managers have to run fast and hard just to keep up with day to day operations. In my work, I've often found that executives who give feedback like what you've been given are themselves lacking in visionary, strategic thinking. Everyone's too damn busy!
Nevertheless, organizations need big picture thinking. I think the single best thing you can do to develop this quality is to devote time to it, perhaps 2-3 hours a week. Use this time to find tools and frameworks, including those mentioned by others in this forum. (I like the Blue Ocean framework myself.) Take a course. Look for articles and white papers on industry trends. Do some formal, or informal, surveying of customers about what they need, want, fear.
Armed with new tools and insights, you can then shift your operating style. Ask questions about consequences, dependencies, long-term as well as short-term costs and benefits. Think, and get others to think, beyond the week, month or quarter. Finally, get yourself placed on teams that are involved with strategic planning in your company. I suspect you have the intellectual horsepower to play in the strategic realms; you mainly need to make time and take concrete steps.